Obesity and back pain, are they related? The simplest answer is yes, excessive body mass increases loads on the spine leading to excessive stress and strain on the tissues and joints of the low back. The effects of mechanical loads and forces on the spine is something that has been discussed already in detail in our blog “Posture in Health and Disease”. However, we did not mention anything regarding obesity during this last blog and I think it is an important area of discussion with patients. Here, we will cover the mechanisms uncovering how obesity and back pain are related and how to solve the problem.
There are those who have concluded that there is in fact no relationship between low back pain and obesity in the published scientific literature1. Whilst Elgaeva et al (2019) state that there is a causal relationship between a person’s body mass index (BMI) and back pain2. This makes it very difficult for patients to understand and appreciate how obesity and back pain are related when there is conflicting information. However, when looking into the literature further, obesity and back pain are related in multiple ways.
First, let’s discuss the biomechanics of obesity and back pain without diving into the math behind it. White and Panjabi (1990) write about how spinal loading scenarios change with increasing central obesity3 as illustrated in Figure 1 below:
The yellow arrow at the front (anterior), represents the persons centre of mass, while the red arrow behind the person (posterior) represents the persons back muscles. For ease of the forthcoming discussion we will describe both of these arrows as lever arms. The spine is represented by the white triangles and rectangles. The spine acts as the pivot point for the lever arms front and back. Much the same as a seesaw in a playground, there are two lever arms either side of a pivot point in the middle. To balance seesaw, the lever arms must be the same length and have the same amount of mass either side. When two children sitting on the seesaw that are the same size, they balance the seesaw and can play happily together. However, if one is a lot bigger or heavier than the other, all the fun stops because the seesaw is unbalanced and neither child can move the seesaw.
Using this simple analogue of the seesaw, we can apply it to the human spine. The further the centre of mass (yellow arrow) moves forward; the longer the anterior lever arm gets. The longer the lever arm gets, the more mass is applied to it, unbalancing the seesaw on one side. The back muscles are only so big, and cannot move away from the spine in the opposite direction to increase the red lever arm length. In order to balance this seesaw, the back muscles must increase their contraction strength. If the yellow lever arm doubles in length, the contraction force of the lumbar spine muscles must double to match it. This increases the loads applied to the spine, which as discussed in our previous blog, triggers a cascade of degenerative pathways by the production of chemicals and enzymes that break down the discs of the spine and causing damage to other tissues.
Arthrosclerosis and vascular changes can also occur with obesity. The same changed that occur with cardiovascular disease where the arteries of the heart become blocked can also happens to the spine. Its is often stated that the discs of the spine are avascular, or without a blood supply. However, this is a misleading statement which can be proven inaccurate from the facts discussed in a previous blog post of ours: “Smoking and Spinal Pain”. In this post we discussed how nicotine from smoking and vaping causes accelerated degenerative changes and damage to the discs of the spine. The simple question therefore is if the discs are avascular (have no blood supply) how can nicotine affect them? The nicotine must be carried to the discs by something, and as nicotine is transported around the body in your blood, it is therefore inaccurate to state the discs have no blood supply. Kauppila (2009) explain how the lumbar spine in particular has branches of the internal iliac arteries branch off forming to iliolumbar arteries, which supply blood to the vertebrae, the spinal muscles, the nerve roots and the discs of the low back4. It has also been identified that the aging disc has increased vascular supply5,6 thus the hypothesis of discs being avascular is rendered moot.
Nevertheless, let’s stay on topic, shall we? When the arteries in your body become blocked, it is obvious that the blood supply is reduced past the blockage. Like the plumbing in your house, if they become blocked, water (and other things) are unable to flow away and a build up of water (and other things) remains in your pipes. In your body, this results in a reduction in oxygen and nutrients to the tissues past the blockage, leading to tissue damage, break down accelerated degenerative changes and low back pain4. Smoking causes the same process, so an obese smoker is at higher risk of suffering low back pain.
Nine time out of ten, when a patient is overweight, the first thing they mention during their initial consultation is “I know I need to lose weight”. Therefore, I generally won’t explain to the patient that they need to lose weight, they already know! The crucial thing is that it is typically the patients back pain that is stopping them from participating in the exercise activities they want to do to lose weight. So, there is a vicious cycle that a lot of people get caught up in where the back pain is driving the weight gain, and the weight gain is also driving the back pain. This becomes very difficult to manage and get yourself out of.
This is how we at Spriggs Chiropractic are different from a lot of chiropractors and other manual therapists. We understand that the pain that brought you into the clinic is likely stopping you from exercising and therefore losing weight. Stating that you may need to lose weight is not helpful for either weight loss nor increasing exercises or low back pain. We work with you to aid in your weight loss with our sister company Spriggs Nutrition, where we can provide you with helpful advice with nutritional support. We are also well equipped with exercise gear for both the management of low back pain and we can give you targeted exercises to help your weight lose at the same time! What a novel concept.
Let’s get your back pain sorted with chiropractic treatment for low back pain, positive dietary modification and exercise in the same place!
Give us a call on 01635 432383 and lets get you started in the right way.
References:
- Ibrahimi-Kaçuri D, Murtezani A, Rrecaj S, Martinaj M, Haxhiu B. Low back pain and obesity. Med Arch (Sarajevo, Bosnia Herzegovina). 2015;69(2):114-116. doi:10.5455/medarh.2015.69.114-116
- Elgaeva EE, Tsepilov Y, Freidin MB, Williams FMK, Aulchenko Y, Suri P. ISSLS Prize in Clinical Science 2020. Examining causal effects of body mass index on back pain: a Mendelian randomization study. Eur Spine J. 2019. doi:10.1007/s00586-019-06224-6
- White AA 3rd, Panjabi M. The Clinical Biomechanics of Spine Pain. In: Clinical Biomechanics of the Spine. 2nd ed. Lippincott Williams & Wilkins; 1990:379-474.
- Kauppila LI. Atherosclerosis and Disc Degeneration/Low-Back Pain – A Systematic Review. Eur J Vasc Endovasc Surg. 2009;37(6):661-670. doi:10.1016/j.ejvs.2009.02.006
- Roberts S, Caterson B, Menage J, Evans EH, Jaffray DC, Eisenstein SM. Matrix metalloproteinases and aggrecanase: their role in disorders of the human intervertebral disc. Spine (Phila Pa 1976). 2000;25(23):3005-3013.
- Kauppila LI. Ingrowth of blood vessels in disc degeneration. Angiographic and histological studies of cadaveric spines. J Bone Jt Surg – Ser A. 1995;77(1):26-31. doi:10.2106/00004623-199501000-00004